Internal-combustion engine



Oct. 31, 1933. H. c. EDWARDS 1,933,246

INTERNAL COMBUSTION ENGINE Filed Nov. 23, 1931 2 Sheets-Sheet 1 gwtmatcw .HEHBEET C. firm 522175.

Oct. 31, 1933. H. c. EDWARDS 1,933,246

INTERNAL COMBUSTION ENGINE Filed'Nov. 25, 1931 2 Sheets-Sheet 2 gwuentoz HERBERT L7. EDNHEDSZ Patented Oct. .31, 193.";

PATENT OFFICE 1,933,246 INTERNAL-COMBTISTION ENGINE Herbert 0. Edwards, Detroit, Mich, assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application November 23, 1931 Serial No. 576,676

. '11Claims.' (G1.121-194) g This invention relates to engines. and more particularly-to crank case construction and cylinder attaching means.

' An object of the invention isto provide an engine which includes a crank case and a plurality of banks of cylinders arranged and se-. cured in a manner to provide a compact light weight structure.

Another object of the invention is to provide an engine in which the cylinders are secured to the crank case in a manner such that explosion forces will not cause localized stresses in the crank case.

A further object of the invention is to provide. a high compression engine in which the cylinders are associated 'with the crank case structure in a manner which will permit the crank case to be formed of relatively thin walls. v

Still another object of the invention is to provide a multi-bank radial engine in. which the crankshaft is formed and mounted so as to permit a compact structure.

Other objects of the invention will appear from the following description taken in connection with the drawings, which form a part of this specification, and in which:

Fig. 1 is a front elevational view of an engine embodying my invention, partially in section, on a line between the two banks of cylinders; Fig. 2 is a vertical sectional view of the engine taken axially thereof taken on line 2 -2 of Fig. 3; Fig. 3 is a plan view ofa fragment taken on line 3-3 of Fig. 1.

Fig. 4 is a perspective view of one of the cylin 'der clamp members turned upside down. 1

Referring now to the drawings by characters of reference, 10 indicates generally the crank case of a multi-bank radial type of high compression engine which is shown formed as a one piece annular 4O end cover 12, secured by bolts 13, and a removable front cover member 14, secured by bolts 15. Intermediate the open front end of the annular casting and the front cover '14, and secured in such relation by the bolts 15, is a flattransversely extending reinforcing wall 16. A similar but removable reinforcing wall l'leis arranged in parallel relation with the wall 16 and is secured by bolts 18 associated with bosses 19 of the casting.

- Between the walls 16 and His formed the crankshaft and rod chamber 20, and between the walls 1'7 and 12 is provided the chamber 21 in which driving mechanism for the valves and accessories (not shown).-can be housed. The crank case formed by the annular casing-.11 and the end casting or forging 11 having a removable rear.

rear end of which is provided with a starter jaw" 25 accessible from the exterior of the rear cover. The crankshaft illustrated is of the two throw type having a pair of pins 26 extending from a relatively large circular intermediate bearing portion 27, and removable counter weights 28 are connected with-the crankshaft arms. The walls 16 and 1'? are formed with hubs in which are ar- )4 ranged roller bearings 29 for supporting the ends of the crankshaft which project therethrough..

A reinforcing disc member or wall 30 is detachably associated within the chamber 20 of the crankcase and is formed with a hub portion 31 in which the bearing 27 of 1 the crankshaft is mounted. This reinforcing disc extends in alignment with an interior flange 32 extending around the crank case and is of slightly less diameter than such flange. The disc member which is preferably formed of light weight steel, serves as part of the securing means for the cylinders, as a reinforcing wall for the interior of the crank. case and as a support for the crankshaft bearing.

,Two rows or banks of cylinders 33 and 34 extend radially from the casing 11 and the cylinders in each row are preferably arranged relatively in staggered relation. Thisstag ered relation is advantageous as the engine illustrated is of the air cooled type and consequently all of the cylinders in each bank will be exposed directly to the air stream. The cylinders extend through openings formed in the casing 11 and are each provided with a flange 35 which engages one of the flat peripheral portions of the casing 11. As best shown in Fig. 3, the flanges of adjacent cylinders in the two rows interfit due to the staggered relation, and consequently, the space required between the rows of cylinders is relatively small thereby aiding compactness and permitting a common cylinder securing mean to be associated with the adjacent flanges of the two rows. The front and rear portion of the cylinder flanges are formed with a groove 36 in their front and rear faces, and such grooves in the adjacent interfitting ends of the flanges in the two rows will align to form a substantially circular groove sur rounding the casing 11.

Tension securing means is associated with the interfitting cylinder flanges, with the front portion of the flanges in the front cylinder row and with the rear portion of the flanges in the rear cylinder row. In the present instance, a tension band means 37 is arranged to surround the forward portions of the cylinders in the front row and a similar band means38 is arranged to surround the rear flangeportions of the rear row of cylinders. Such band means preferably comprises a plurality of sections 39 havingtheir adjacent ends threaded in opposite directions and connected by turnbuckles 40. The turnbuckles are arranged so that they are located intermediate cylinders and the band'sections 39 are arranged to seat in the full length of the groove formed in the front portions of the front cylinder flanges and in the rear portions of the rear cylinder flanges. These band means, .through means of the turnbuckles, are placed in tension which is greater than that to which they are subjected by the maximum explosion forces in the associated cylinders, and it is thus obvious that the crank the flanges of the cylinders in the two rows are formed with grooves 36 which align when the cylinders are assembled on the crank case, and extending between the corners ofsuch adjacent cylinder flangesl provide the clamp members All which are formed with a boss 42 on the under side which fits into and seats in the adjacent ends of the flange grooves 36. The crank case flange 32 is formed with radially extending openings through which studs 43 extend, such studs being fastened in the rim portion 44 of the reinforcing steel disc 30. The outer end of the studs extends, through openings 45 arranged centrally through the clamp members til, and a nut 46 is associated'with the end of each projecting stud. The studs are of less diameter than the openings in the flange 32 and are consequently freely movable radially with respect to the casing 11. By screwing the nuts 46 down on the studs, the flange 32 and the head 4.4 of the disc will be drawn together and .consequently the disc member will be properly centered and placed in desired tension. This connecting means will clamp the bridge members against the cylinder flanges and thus the cylinders are securedto the casing 11 in a marinerv such that the casing will be compressed in a line I with the disc member 30.

With this method of securing the cylinders to the crank. case, it will be clear that as the bands are tightened and the disc member placed in tension, compressive stresses will be set up in the crankcase, or, in other words, the crank case will be compressed because of the cylinder flanges being pressed thereagainst and will act as a base. The bands are preferably tightened about the crank case and the bolts are screwed into the disc until the tension in the bands and the disc is considerably greater than any pressure that may be developed in the cylinders due to the expansion of the explosive mixture after combustion in order to hold the cylinder flangesagainst the crank case under all conditions and with the desired factor of safety. In this eas es r manner, the crank case is entirely relieved of any tensile stress resulting from the expansion of the explosive mixture in the engine cylinders during operation of the engine, as the tendency of the explosive forces to move the cylinders radially outwardly is not' transmitted to the crank case as would be the case with bolts fastened to the" crank case securing the cylinders in place. 7

It will be further seen that the compression bands and the disc serve to absorb loads from the cylinders and to distribute them uniformly around the crank case, such" cylinder loads being caused during engine operation and resulting principally from explosion forces in the cylinders, side thrust of the pistons. on the cylinders, and vibration.

In order to prevent the cylinders from becoming displaced from the crank case when the tension securing means is removed, I provide clip members 56 which engage flanges of adjacent cylinders in each row and are secured to the casing 11 by studs 47 and nuts 48 which are screwed on the outer end of the studs. Upon removal of the cover 12 and the counter weights 28, the crank shaft and the wall 17 can be removed from or inserted into the crank case, the arms of the crank being short enough to pass through the hub of the disc 30.

It' will be seen that with the structure described, I am able to provide a lightweight, rugged and compact engine of a multi-cylinder radial type. v

While I have herein described in some detail a specific embodiment of my invention, which 1. deem to be new and advantageous and may specifically claim, I do not desire it to be understood that my invention is limited to the exact details of the construction, as it will be apparent ing radially from the crank case, a flange 011 each cylinder bearing against the crank case; a separate wall extending transversely in the crank case, the outside diameter of said wall being of slightly less diameter than the adjacent interior wall of the crank case, and adjustable means extending through the crank case connecting the flanges and the separate wall, said means being adjusted to place the separate Wall in greater tension than that transmitted thereto by explosion forces in the cylinders.

2. In an internal combustion engine in combination, a crank case, radially extending cyhn= ders having a portion engaging the outer sur face of the crank case, a steel disc traversing and less in diameter than the interior of the crank case, and adjustable connecting means between the disc within the crank case and the portion of the cylinders bearing against the crank case, said connecting means" passing through the crank case and placing the disc in tension greater than that transmitted byexplosion forcesin the cylinders.

3: In an engine, a crank case, cylinders associated with the crank case, a transversely extending disc member within the crank case, said disc member being of less diameter than the interior of the adjacent wall ,ofthe crank case, and adjustable means connecting the cylinders with the disc member, said connecting means exten through the crank case but out of 154) contact therewith and being adjusted. to place the interior of and of less diameter than the interior of the case, a crankshaft having a central bearing mounted in the reinforcing Wall, and means extending through the crank case and connecting the cylinders with the wall, said means constantly maintaining the wall in tension with the central bearing in centered position.

5. In an internal combustion engine, a crank case, two banks of cylinders extending radially from the crank case, flanges extending from the cylinders and bearing against the crank case, a wall in the crank case of less diameter than the interior diameter of the crank case, means securing the adjacent flange ends of the two banks of cylinders against the crank case and to the wall in the crank case, said means placing said wall in high tension, and an individual tension means securing the other flange ends of each bank of cylinders against the crank case.

6. In an engine, a crank case, banks of cylinders extending radially from the crank case, flanges extending from the cylinders and bearing against the crank case, the adjacent flange ends of the cylinder banks having grooves therein, bearing members engaging in the grooves of adjacent flanges in the cylinders of adjacent banks, a reinforcing wall within the crank case said wall being spaced separate and spaced from the crank case, and means extending through the crank case and connecting and securing the bearing members to the reinforcing wall, said means maintaining the reinforcing wall in high tension.

7. In an engine, a crank case, banks of cylinders extending radially from the crank case, flanges extending from the cylinders and bearing against the crank case, the adjacent flangesof the banks of cylinders being staggered and interfltting, means bridging the adjacent corners of the interfitting flanges, a reinforcing wall within and of less diameter than the crank case, and connecting means between the Wall and each of the bridge means, said connecting means extending through the crank case and placing the wall in tension.

8. In an engine, a crank case having an inwardly extending circular flange, cylinders having portions engaging the crank case periphery, a circular Wall in the crank case in alignment with the flange, said wall being of less diameter than the opening formed by the flange and spaced therefrom, and securing means connecting the wall and the cylinders, said securing means extending through the crank case wall and securing the circular-wall in tension against the flange.

9. In an engine, a crank case, a transversely extending wall in the crank case, said wall having a crank shaft bearing therethrough and being of less diameter than the interior of the crank case, cylinders bearing against the crank case periphery, and means passing through the crank case connecting the wall and the cylinders together, said means placing the wall under high tension with the bearing in centered position.

'10. In an engine, a crank case, cylinders bearing against the crank case, a removable wall of less diameter than the interior of and extending transversely in the crank case, a crank shaft in the case supported by the removable wall, and means connecting the wall and the cylinders, said means passing through the crank case wall and maintaining the removable wall in high tension. 11. In an internal combustion engine, a crank case, cylinders having means bearing against the crank case, a separate interior wall traversing the crank case, the periphery of said wall being spaced from the adjacent wall of the crank case, and tie means connecting the cylinders to the interior wall and placing the wall in high tens1on.

HERBERT C. EDWARDS. 

